Brownfields_Content Page_Dry cleaning contamination

Dry cleaning contamination

The dry cleaning industry began long before there were rules to manage chemical wastes. This includes liquid wastes (wastewater) and solid wastes (sludges and used filters), both of which are contaminated with the chemicals used for the dry cleaning process.

The soil, groundwater and sewers beneath and adjacent to historical dry cleaners may have been contaminated through the disposal of the chemical waste into sewers and/or spills and dumping on the property. Many former dry-cleaning properties have been redeveloped, but contamination from historical operations was left behind.

When evaluating and cleaning up sites with a history of dry cleaning operations, it is helpful to understand past processes, chemical uses, waste generation and management practices, and the mechanisms by which contamination entered into the environment.

If you have questions about your dry cleaning facility or a cleanup you are involved with, contact your regional Remediation and Redevelopment project manager.

For more information about the licensing requirements for dry cleaners, visit the Department of Revenue website.

The Dry Cleaner Environmental Response Fund (DERF) reimburses the investigation and cleanup costs of contamination caused by dry cleaning chemical discharges. The DERF Program has been closed to new applicants since Aug. 30, 2008. 
 

History of Chemicals Used in Dry Cleaning

Prior to the 1940s, trichloroethene (TCE) was the preferred chemical for dry cleaning because it wasn’t flammable. Dry cleaning was done with chemicals like gasoline in the past, which sometimes resulted in fires or explosions. Using TCE was safer and meant that dry cleaners could find insurance policies for their business more easily.

During the early 1940s, the United States military was busy fighting World War II (WWII) and TCE, a chemical commonly used in dry cleaning, was being used more and more as a helpful agent to clean weapons and produce metal parts for the soldiers overseas. TCE production would increase almost 400% by 1944 and would be considered a critical national security resource.

The shortage of TCE for civilian use would force dry cleaners to use the substitute chemical cleaning solvent perchloroethylene (PCE), allowing TCE supplies to be prioritized for the mass production, repair and maintenance of military machinery and weapons, especially airplane parts. What wasn’t known at the time were the unintended consequences of PCE on the environment and health of our communities for decades to come.

PCE continued to be the primary chemical used by dry cleaners from WWII until the 2000s. Although dry cleaners were the largest consumers of PCE, it was also used in suede protectors, paint removers, furniture strippers, water repellents, silicone lubricants, spot removers, glues and wood cleaners. However, dry cleaning delivery methods, machine technology and waste and wastewater disposal practices did not meet today’s standards, which resulted in dry-cleaning chemicals like PCE ending up in the ground, groundwater or sanitary sewers.

Unintended Consequences of Small Leaks
Even a small spill or leak of dry-cleaning chemical matter – like a gasket that leaks just once each second – can release hundreds of gallons of solvent in a single year. PCE does not degrade easily and can exist in the ground for decades. It can also migrate due to gravity, spreading out beyond the original spill location. PCE can harm the environment further by entering the groundwater, which in turn could be consumed and be a risk to human health.

It wasn’t until the 2000s that it was widely recognized that historical dry-cleaning chemical spills and disposal could also result in unhealthy indoor air quality conditions. Vapors emanating from contaminated soil, groundwater or sanitary sewers can enter a building, typically through cracks or gaps in the foundation – this is called vapor intrusion. The vapors bring chemicals into the indoor air, which can cause unsafe indoor air quality conditions and result in adverse health effects to building occupants. The contaminated vapors are often odorless and colorless, making them hard to identify without special testing.

The dry cleaning industry has changed substantially in the past century. At its peak, there were over 21,000 dry cleaning locations in the United States. Today, there are fewer dry cleaners than ever due to changes in fashion trends and advances in textiles, such as the invention of the wrinkleless shirt. Developments in eco-friendly cleaning solutions and better regulations have also added to a significant reduction in the amount of PCE used by dry cleaners today. Many of the former dry cleaner locations have since been redeveloped into different businesses. Even though the dry cleaning business may be gone, any prior spills or leaks of cleaning chemicals may continue to hide below the surface.

Changes in Dry Cleaning Machines and Regulations

After the introduction of the newest generation of machines, it took some time for the older machines to be replaced. Although second-generation machines came on the market in the late 1960s, 34% of dry cleaners still used first-generation machines in 1991. The 1990 amendments to the Clean Air Act impacted dry cleaner operations by preventing the opening of machines until vapor concentrations fell below certain concentrations. By 2000, only 4% of dry cleaners were using first- or second-generation machines, and by mid-2008, transfer machines using PCE were no longer allowed.

DNR Involvement

The DNR created an internal team in the 1990s to help historical dry cleaners investigate and clean up properties that left behind contamination. The Dry Cleaning and Vapor Intrusion Team (DVIT) provides training and resources to the public, from environmental scientists who help clean up contaminated sites to people who might be affected by vapor intrusion. Although the historical use of PCE in dry cleaning has had unintended negative and lasting implications for human and environmental safety, the DNR continues to identify new ways to work with partners to mitigate risk, create public awareness and identify potential areas of concern regarding vapor intrusion.

Vapor Intrusion Prevention & Partnership Toolkit

The Vapor Intrusion Prevention & Partnership Toolkit provides resources on how to proactively protect the health of your community by preventing exposure to vapor intrusion.

Dry Cleaner Remediation Training

The State Coalition for Remediation of Drycleaners (SCRD) members and CLU-IN hosted a webinar on June 8, 2011, titled "Conducting Contamination Assessment at Drycleaning Sites." Former RR Program hydrogeologist Terry Evanson was one of four presenters during the online training.

Key aspects of the updated guidance were presented, including: an overview of the drycleaning process; chemicals used; waste generation and management practices in the drycleaning industry; site reconnaissance; identifying sampling locations; and environmental assessment technologies applied to drycleaning facilities. The seminar can help state regulators and practitioners identify likely areas of contamination and more effectively implement investigation approaches at current and former dry cleaning facilities.

Since 2011, there have been significant advances in the understanding of contaminant vapor movement, specifically vapors resulting from dry-cleaning chemical contamination, and the science related to the investigation and mitigation of vapors. Guidance specific to vapor intrusion can be found on our Vapor Intrusion for Environmental Professionals webpage. Specific training regarding advances in vapor intrusion beginning in 2014 through today can be found on the Remediation and Redevelopment Program Training Library webpage.

Resources

For more information, contact